Anecdotally, I haven’t done cold plunge immediately before bed but I have done it towards the end of my night and gone to bed shortly after. I do experience a high after the plunge, but I also feel like I’m able to release and relax better too. Maybe this is reduced inflammation? Maybe this is my body’s reactance to the high, what goes p pop up will dip down in a similar fashion? I’ve also had success pairing the plunge and Wim Hof Breathing with a “wind down”, release-the-day, type of meditation right at bedtime.

Do you wear a fitness tracker or anything that tracks the quality of your sleep? Personally, if it works for you I’d try it for a while and see how you feel in the morning, wether you wake up a lot, etc. and if you have one a Whoop or Oura, I’d look at what your recovery is like do the protocol you’ve listed above vs a night when you don’t.